Apparatus for delivering articles to and discharging articles from aircraft while in flight



DSG 29, 1942. R. c. DU PONT ET AL 2,306,690

APPARATUS FOR DELIVERING ARTICLES TO AND DISCHARGING ARTICLES FROM AIRCRAFT WHILE IN FLIGHT Filed May 18, 19:59

I5 Sheets-Sheet l Dec. 29, 1942. R'. c, DU PONT ET Al. 2,306,690

APPARATUS FOR DELIVERING ARTICLES TO AND DISCHARG'ING ARTICLES FROM AIRCRAFT WHILE IN FLGHT Filed May 18, 1939 5 Sheets-Sheet 2 l INVENTORS 51 fifa/mm a da fm/ c. DU PONT ET AL 2,306,690

Dec. 29, 1942. R

APPARATUS FOR DELIVERING ARTICLES To -AND DISCHARGING ARTICLES FROM AIRCRAFT WHILE IN FLIGHT 3 Sheets-Sheet 3 Filed May 18, 1959 INVENTORS ayfdffzes Hay ATTORNEY Patented Dec. 29, 1942 @EEE STATES EN@ erica APPARATUS FOR DELIVERING ARTICLES TO AND DISCHARGIN G ARTICLES FROM AIR- CRAFT WHILE IN FLIGHT of Delaware Application May 18, 1939, Serial No. 274,329

4 Claims. (Cl. 258-1) In the operation of aircraft, it is often desirable to either pick up from or deliver to places along the route of said aircraft, articles, such as mail, express, or pieces of freight. Frequently, the localities from which the articles are to be picked up or to which the articles are to be discharged, are so situated that it is not practical to makeV a lan-ding at the localities, or the amounts to be picked up or discharged are so small as not to Warrant the expense cf interrupting the flight of the craft Vfor a suilicient period to land and pick up, Aor discharge the article. Also, the time that is necessary to land, stop the craft, and take off again may be so great as to render such' a service impraotical This invention overcomes these obstacles by providing a means by which articles may be discharged from an aircraft while in Hight or picked up by the aircraft while in flight or both operations may be performed substantially simultaneously.

In making such a pick-up or discharging articles from an aircraft, it is desirable to interrupt the flight of the plane as little as possible. In view of the tremendous speed at which aircraft now operate and in View of the possible addition to that speed 'by virtue of the direction of the air current, it is obvious that the problem of overcoming the shock incident to a pick-up or delivery is very important. The instant invention, while presenting a simple and effective means for picking up and delivering articles also presents an effective medium for absorbing the energy incident to either the pick-up or delivery,

stantially automatic as far as the pilot is conl' cerned. It is merely necessary for him in making the delivery to so navigate the ship that it will come over a designated point at a desired altitude.

It is also necessary when navigating a ship close to the ground with objects trailing therefrom to provide a means by which those objects may be quickly released in the event that they should become entangled in any substantially secure object on the ground. The present invenv tion contemplates this and provides an automatic release if an `object is encountered which offers a resistance which might be detrimental to the aircraft.

It is well known that the air currents about a craft while in flight will affect seriously any object being brought close to the aircraft. For this reason, it is necessary to provide any object of substantial size which is intended to be brought in to the aircraft or to be discharged from the aircraft With a shape such that it will be affected to a minimum by the air currents about the -aircraft and at the same time will be governed, to a maximum degree, by the means by which it is connected to the aircraft. In the present invention, a container for articles to be picked up or discharged from the aircraft has been provided which is so shaped that it meets the heretofore mentioned requirement.

Various other features and advantages of the invention will be apparent from the following particular description and from an inspection of the accompanying drawings.

The invention also consists in certain new and original features of constr-uction and combinations of parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, and the manner in which it may be carried out, may be better understoodby referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which Fig, 1 is a view in elevation of a ground station adaptable for use in connection with an aircraft used in making a pick-up and delivery.

Fig. 2 is a diagrammatic, perspective View showing the ground apparatus with relation to the aircraft just as a pick-up and delivery is about to be made.

Fig. 3 is asimilar view showing the relation between the aircraft and ground equipment just after a pick-up and delivery has been made.

Fig. 4 is a diagrammatic view in cross-section of the apparatus within the aircraft for suspending the delivery and pick-up lines from the aircraft. Y

Fig. 5 is a longitudinal sectional view of a desirable burden container for use `in vthe system.

Fig. 6 is a view of a sliding connection for use in attaching the burden to the pick-up and delivery line.

Fig. '1 is a view of a modified form of sliding connection.

Fig. 8 is a detailed view of a desirable mecha nism for connecting the pick-up and delivery line to the ground station and to the trailing line from the aircraft.

The ground apparatus as shown particularly in Figs. 1, 2, and 3 comprises generally a plurality of masts or uprights I which are preferably hollow. These masts. or uprights, are mounted in the ground in a substantially upright position.

At a suitable point intermediate the upper and lower ends of the upright, may be located a cutaway section in the upright I which provides a support 2 for a pulley 3. The pulleys 3 are preferably located with their axles substantially flush with the outer edge of the upright so that onehalf of the pulleys will be on the outside of the upright and half on the inside. Hoist lines 4 are adapted to pass over the pulleys 3 with the upper end of the hoist lines 4 passing through the upright I'and out over the pulleys 3 with a weight B attached thereto. To these weights or to the end of the lines 4 may be attached shock absorbers 1 by any suitable means. Suspended between the shock absorbers 1 and secured thereto by suitable means is a burden-retaining or catch line 5.

The lower end 5 of the hoisting line 4 may pass through a hole I2 in the upright I and then into boxes Il located on the outside of the upright I. A winch II may be provided in each of the boxes Ii on which the ropes 4 are adapted to be wound up in order to hoist or lower the burden-retaining line In the event that it is desired to detach the burden-retaining line 8 and the shock absorber 1 from the hoisting line 4, the weights 6 have been provided so that with the burden-retaining line detached, the hoisting line 4 may be raised and the weights brought up ush against the outside of the upright I. When it is again desired to attach the retaining line 8, the hoisting lines -tl may be payed out from the winch II. The weights 6 will cause the ends of the hoisting lines G- to descend so that the retaining line 8 may be reattached.

Adjacent the upper end of the upright I are cutaway sections forming a housing or support I5 for upper pulleys I6 over which hoisting ropes 1 are adapted to pass. Attached to these ropes adjacent their upper end and exteriorly of the upright I may be weights I8 for the same purpose as the weights 6 on the lower hoisting lines 4. A snap-hook 20 may be provided in the end of the weights I8 or suitably connected thereto. This snap-hook is adapted to fasten into a releasingr link or breaking link i9 which may be attached to a burden line 2l. The lower end .'52 of the ropes I1 may pass through holes 23 into the boxes Ill where they are adapted to be wound up on the Winches II. In addition to the breaking link I9 the pick-up and delivery line 2l may have weights 24 in the shape of monkeys fists attached thereto adjacent its end.

Each upright I may be provided with a cap I3 which protects the upper pulley I6 and the openings and support l5 against the entrance of snow and ice and facilitates the operation of the ropes during bad weather. Each upright may also be provided with a marker pole 25, having a suitable indicating or marking flag 23 attached thereto.

The aircraft for effecting the pick-up and delivery is designated generally as 39. There may be mounted within the fuselage 65 of the airg craft 30 a piston and cylinder supporting frame 3| carrying a cylinder 33 adapted to slide over a piston 32. Mounted on the cylinder 33 and preferably adjacent its lower end is a socket 34 into which a ball 35 attached to a pick-up line 35 is adapted to be fitted.

Mounted within the fuselage there may be a pulley or groove 31 which is adapted to receive the pick-up line 33 and guide it as it leaves the aircraft.

A winch 38 onto which the pick-up line 36 may be attached may be provided adjacent the cylinder 33. Adjacent the other end of the burdentransferring line 36 and intermediate a grapple 39 may be provided a breaking link or Weak section 54. The grapple 39 may be of any conventional type.

In addition to the pick-up line 33 there may be trailed from the aircraft 39 a delivery line 50 which preferably has a ring 5| in the upper end of it and a ring 52 in the lower end also. This line passes over a groove or pulley 55 located .in the fuselage 65. The ring 5| is adapted to fit over a pivotal member 53 which is pivotally attached to the fuselage of the aircraft as at 54.

Cooperative with the pivotal member 53 and adapted to lock against it to prevent it swinging down and thus releasing the ring 5I except when desired, may be located a second pivotal member 56 pivoted to the fuselage 65 as at 51. Attached to this second pivotal member 55 at any desirable point, such as 58 may be a control rope 59 which preferably passes over a guiding pulley or other roll 69 attached to the fuselage of the plane and thence to another guiding member 6I and down to a tripping release 62 pivoted as at 63 to the fuselage of the aircraft.

The burden container best suited for use in a system such as that contemplated in the present invention is shown in Fig. 5 generally as 40 and comprises a nose section 4I, a first semi-rigid skirt portion 42 connected thereto and a second canvas skirt portion 43 connected as shown to the first skirt portion 42. In addition, there may be means 44 provided thereabout through which a strap of any conventional type may be inserted to close the canvas skirt portion. A nose ring or snap-hook 45 may be provided in the nose section 4I of the burden container 4D whereby it may be connected to whatsoever means by which it is to be carried.

As is clearly shown in Fig. 5, the burden container presents an enlarged nose section 4I with a body 42 and 43 each succeeding section being smaller in its outside diameter than the outside diameter of the next preceding section. In addition to this shape, the contour of the container is broken as at 45 and 41. Thus, air passing over it will be spoiled and caused to flow turbulently or burble, As a result, when a pull is applied to the large end by a line from an aircraft, the container will tend to trail smoothly with a minimum of gyrating. In addition to these features, the skirt 43 is collapsible and can be folded up at the desired point. As a consequence the burden may be carried in the container so that the center of gravity will be at a desired point. This will aid in making the container trail smoothly.

The burden container shown in Fig. 5 is described and claimed in du Pont application Serial No. 304,890 led November 17, 1939, now Patent No. 2,298,688, dated Oct. 13 1942.

In Fig. 6 is shown a particular type of sliding connection 13, particularly adapted for connecting the container tothe burden line. The connection 18 comprises broadly two cheek pieces 'H and 'l2 with two substantially parallel ovalshaped members 13 and 'M pivotally depended therebetween as by the pivotal connections as l5 and 16. The members 'i3 and 'Mare spaced apart and define with the cheek pieces and 'l2 a passage to admit a line. A strap member 'l1 with a ring 'i8 therethrough may be provided to be connected to the nose ring or snap-hook t5 in the container t6.

The sliding connection or slider 'Hi and its cooperation with the rest of the system is described and claimed in Yesulaites application Seriall No.v 313,235, led January 10, 1940.

In Fig. 7 is shown a modied form of the sliding connection, designated generally as 80, which comprises a block. member 8| with a curved passage 62 therethrough.

In Fig. 8 is shown a desirable breaking link I9 which comprises generally a spring link member 43 with a gap 49 therein. Thus, when a second link is inserted therethrough, it may be withdrawn if the force exerted on it is greater than the tensile strength of the link I8.

The operation of the system and apparatus, assuming'that itis desired to pick up from the ground an object or other matter which can be put into a container, is as follows:

The hoist lines |1 are lowered to a point adjacent theground and the burden line 2| with the container lill connected thereto as by the sliding block 'lil is attached to the snap-hook 20 in the end of the weights I8 on the ends of the hoisting line. The lower ends of the hoisting lines are then attached to the Winches ll and the hoisting lines wound up thereon until the burden line 2| has approached to a point adjacent the upper ends of the uprights The aircraft 3i! is then put into the air and when it has reached a sufficient altitude, the pick-up line 36 with the grapple 39 rattached thereto with the weak link or breaking link 64 therebetween is lowered from the aircraft a desired distance. This distance is preferably adjusted so that the grapple 39 hangs a desirable distance below the aircraft.

The aircraft is then flown in such a manner that the grapple 39 will pass below the burden line 2| suspended on the uprights I. As the pickup line 35 strikes the burden line 2|, it will put a suilicient force thereon to break the breaking links i9 away from the connecting link 20. Thus, the burden line with the burden container attached thereto will be broken loose from the uprights.

If, as is shown in Figs. 2 and 3, the pick-up line 36 trailing from the aircraft strikes the burden line 2| between the point where the burden container itil is attached to the burden line 2| and .g5

the right hand upright, the burden line 2l will slide relative to the pick-up line 36 until the burden line 2| comes into the bills of the grapple 39.

At this point, it is obvious that the burden line 2i must assume the speed of the aircraft. i;

The acceleration of the burden line at this point will be very rapid and would throw a tremendous strain upon the burden and burden container it unless there were some energy absorbing means interposed. As is shown clearly in Fig. 6, the 'v' sliding connecting member 'l0 with its two substantially parallel pivotal members 73 and 'It with the ropes 2| passing therebetween will have a tendency to turn so as to bring the two parallel members |3 and 74 to press strongly upon the line 2 l. VIt can be seen from Fig. 3 that the maximum turning effort exerted will occur as the pick-up and delivery line 2| is grabbed by the grapple 39. Thus, the resistance to slipping will be at a maximum when the resistance to movement is at a maximum and the burden line 2| will slowly slide through the parallel members. As a result, the burden container will be slowly accelerated and as it accelerates the turning moment on the block 'lil will diminish with the result that the grip on the line 2| will diminish.

By properly proportioning the distance between the members 'I3 and l@ with relation to the size of the pick-up and delivery rope 2|, the amount of friction between the burden line 2| and the members 13 and 'It will be so ad- `justed due to the changein resistance of the burden and thetensile force exerted by the grapple and delivery line 39 and 33 respectively that Vthe friction between them will balance out at a certain point, usually before the sliding connection 'l0 has come to the end of the burden line 2|. In the event that the friction is not sufficient to stop the sliding member 'lil from going to the end of the burden line 2| the weighted members 21| are provided which present an enlargement over which the sliding member cannot pass.

The operation of the fixed slider or block 30 of Fig. '7 will be similar to that of the pivoted slider of block 'l0 just described in that the friction between the block and the line it grips limits the accelerating force applied to the burden 4B; except that, in the case of fixed .block 8l), due to the Xed nature of its tortuous path 32, the friction between it and the line passing therethrough will remain more uniform.

n addition to the shock absorbing means thus provided, the piston and plunger in the aircraft designated in Fig. 4 as 32 and 33 respectively, with the socket 34 into which the ball 35 on the pick-up line 3S fits will also serve as a shock absorber. The throw of this shock absorber is limited by the dimensions of the aircraft and therefore only a limited amount of energy may be absorbed here. This will, however, prevent the passage of any tremendous shock to the aircraft.

Once the burden line 2| has been grabbed by the grapple 39 the delivery line 3S may be'wound into the aircraft by means of the winch and the burden and burden-container deposited in any desired place.

In discharging articles from the aircraft two systems generally may be employed. In one of these, illustrated in Fig. 2, the article to be olischarged from the aircraft is trailed on a length of the burden line 2| attached to a line 5.53. The line 56 is payed out from the aircraft and when it has reached the end, the connection 5l is attached to the pivotal member 53.

The aircraft is then operated in such a manner as to bring the burden line with its burden lil attached thereto between the uprights l. The burden-retaining line 8 is suspended between the uprights and connected to the hoist lines 4 as by the shock absorbers 'l' which are attached to the weights 6 on the upper end of the hoist lines 4.

The aircraft is flown at such an altitude that the burden to be discharged will pass between the uprights and at an altitude such that it will be between the ground and the burden-retaining wire 3, yet the connection between the breaking link I9 and the ring 52 in the end of the discharge line 5B will pass above the burden retaining line 8. As the rearward burden line 2| strikes the burden retaining line 8, it is obvious that a tremendous force will be built up on the breaking link i9 which will cause it to release from the ring 52.

The weighted ends 24 of the burden line will of course tend to continue in their normal path but being resisted by the burden retaining line 8 their energy will be resolved into a circular motion with the result that the rearward burden line 2l with the burden L59 attached thereto will be suspended upon the burden retaining line 8.

In another system of delivery illustrated in Fig. 4, the delivery line 58 on which the burden to be delivered is suspended, is attached directly to the pivotal member 53 within the aircraft. The aircraft is then navigated in such a manner that it will come over a desired point at a desired altitude. It is obvious that the pilot at this time is occupied with controlling his craft due to the proximity to the ground and the possibility of obstructions being in the way. For this reason his attention must not be distracted by having to perform any additional operations.

It is possible, however, to put a control member on the side of the aircraft adjacent the pilot which may be struck by his knee with a very simple movement. For this reason, there is provided the pivotal member E2 pivoting on a point Y S3 with the connecting cord 5S attached thereto.

As the aircraft arrives over the desired point to make a discharge the pilot strikes the pivotal member 62. This member is so pivoted that any movement of the pivotal member will tend to lengthen the distance between t-e end of the pivotal member 62 and the point 58 on the pivotal member ES. With the result, since these two points are connected by the line 59, the point 58 will have to move up toward the point l, and I consequently will pull the pivotal member 5S away from the pivotal member 53, thus allowing the pivotal member 5I to swing down and allow the burden line 2i with its connection thereon to slide over the pivotal member 5i and be released frorn the aircraft.

It is obvious that there may be times when it will be desirable to perform either of the systems of delivering articles at the same time that one is making a pick-up of an article from the ground. It has been found that by making the grapple 39 of a sufficient weight and making the pick-up line 3G of a sufficient weight and thickness, this line will tend to swing down from the aircraft in a fairly straight line. other hand, the line 5G with the burden attached thereto will tend to trail out behind the aircraft and away from line 35. As a result, these two lines may be payed out from the aircraft at the same time and will not become entangled. Consequently, it is possible to so navigate the aircraft that the grapple 39 will pass between the suspending line 8 and the burden line 2| on the ground station and at the same time the burden line 2i attached to the strike the retaining line 8 and leave the article deposited thereon. If it is not desired to do it this way, the retaining line 8 may be omitted and the release S2 tripped at the desired point.

The terms and expressions which have been Y employed are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding discharge line 53 will any equivalents of the'features shown and described, or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

What is claimed is:

l. In an air pick-up system, a ground station comprising spaced poles, a burden line having enlargements at the ends thereof, frangible ccnnec tions between the ends of said burden line and said poles, a burden, a friction block connected to said burden, said block being of one-piece construction and having a tortuous passage through which said burden line passes with a snug fit, an aircraft, a pick-up line depending from said craft having a grapple at the lower end thereof, said grapple being adapted to engage said burden line when said craft flies over the ground station to pick up the burden, said block having sucient frictional engagement with said burden line to impart a limited accelerating force to said burden, the enlargements on either end of said burden line preventing said block from sliding oi the line.

2. In an air pick-up system, a ground station comprising spaced supports, a burden line having enlargements at the ends thereof, frangible connections between the ends of said burden line and said supports, a burden, a friction slider connected to said burden, said slider having a passage through which said burden line passes with a snug fit, an aircraft, a pick-up line depending from said craft having pick-up devices at the lower end thereof, said pick-up devices beiner adapted to engage said burden line when said craft nies over the ground station to pick up the burden, said slider having sufficient frictional enengagement with said burden line to impart a limited accelerating force to said burden, the enlargements on either end of said burden line preventing said slider from sliding off the line.

3. In an air pick-up and delivery system, a ground station comprising spaced poles set in the ground, an upper burden line having frangible connections with said poles, a lower receiving line, shock absorbers between the ends of said receiving line and said poles, an aircraft, a pick-up line depending from said craft having a grapple on its lower end, a delivery line depending from said craft and trailing behind said pick-up line, a second burden line having Weights on the opposite ends thereof, a burden attached to the lower end of said second burden line, a second-mentioned frangible connection between said delivery line and said burden line whereby, when the aircraft flies over the ground station, the pick-up line engages the rst burden line with the grapple above said delivery line and thereafter the second burden line engages said receiving line, causing the second-mentioned frangible connection to break and one of said weights to rotate around the receiving line.

4. In an aircraft pick-up system, an aircraft, a burden to be picked up by said aircraft while in flight, devices for establishing yieldable connection between said aircraft and said burden, said devices comprising a line and a slider for jointly pulling said burden, said slider having a passage snugly fitting said line to frictionally grip said line, the friction between said slider and said line applying a limited accelerating force to said burden without rebound.

RICHARD C. DU PONT. JAMES G. RAY. 

